JPH11313691A - Production of modified polyester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain various modified polyesters under simple and mild conditions not followed by a side reaction by reacting a lactone with a polyester in the presence of a hydrolase such as lipase or the like. SOLUTION: A lactone [e.g. dececanolide (13-membered ring lactone) or the like] is reacted with a polyester [e.g. poly(ε-caprolactone) or the like] in the presence of a hydrolase such as lipase at 60 deg.C for 72 hours under mild conditions not followed by a side reaction so that both a transesterification reaction between poplyester molecules and a ring-opening polymerization reaction of the lactone occur. Consequently various modified polyesters comprising a copolymerized polyester is simply obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a modified polyester, which comprises reacting a lactone with a polyester in the presence of a hydrolase. More specifically, the present invention relates to a method for producing a modified polyester under simple and mild conditions.

[0002]

2. Description of the Related Art Various types of modified polyesters have been synthesized so far. For example, aliphatic polyesters are usually prepared by subjecting three or more kinds of dicarboxylic acid alkyl esters and diols to a temperature of 150 ° C. or more using a chemical catalyst. Manufactured under high temperature. Therefore, a reaction under mild reaction conditions has been desired since a side reaction occurs. In addition, although the polymerization of lactones proceeds under relatively mild conditions, there is a problem in that a tin compound is used as a catalyst and toxicity is high.

On the other hand, it has been shown that polyesters can be synthesized under mild conditions using an enzyme catalyst.
For example, Chem. Lett. , 1149 (1993) discloses a method of synthesizing a polyester by promoting ring-opening polymerization of ε-caprolactone using a lipase catalyst. However, there is a problem that the structure of the polymer is limited because lactones are used as monomers. Polyesters produced by microorganisms include, for example, homopolymers such as 3-hydroxyalkanates, and attempts have been made to synthesize copolymers for the purpose of changing the physical properties of the polymers (polymers, Vol. 42, No. 11, 1993). However, the production of copolymerized polyesters has a problem that only a limited amount of copolymerized polyesters which are metabolized by microorganisms can be produced, and various modified polyesters can be produced under mild conditions without side reactions. There has been a demand for a method for producing such.

[0004]

The present invention relates to a method for producing a modified polyester, which comprises reacting a lactone with a polyester in the presence of a hydrolase. More specifically, the present invention relates to a method for producing a modified polyester under simple and mild conditions.

[0005]

That is, the present invention relates to a method for producing a modified polyester, which comprises reacting a lactone with a polyester in the presence of a hydrolase.

[0006] The present invention further relates to a method for producing a modified polyester in which the hydrolase is lipase.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides that when the lactone ring-opening polymerization is carried out in the presence of a polyester, both a transesterification reaction between the polyesters and a polymerization reaction of the lactones take place, thereby giving a copolymerized polyester. We are using.

The polyester used in the present invention is not particularly limited as long as it reacts with a hydrolase, but polyesters synthesized from various polycarboxylic acids or their ester derivatives and polyhydric alcohols, or Including polyesters synthesized from various hydroxy acids or their ester derivatives or cyclic monomers.

Examples of the polyvalent carboxylic acid which is a monomer component constituting the polyester include citraconic acid, malic acid, citric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid. Acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, tetradecanedicarboxylic acid, fumaric acid,
Itaconic acid, maleic acid diglycolic acid, aliphatic carboxylic acids such as dimer acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylene diacetic acid, m-phenylenediglycolic acid, p-phenylenediglycolic acid, o-phenylenediglycolic acid, diphenylacetic acid, diphenyl-p, p'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid Acid, naphthalene-2,6-dicarboxylic acid, anthracene dicarboxylic acid, trimellitic acid,
Aromatic carboxylic acids such as pyromellitic acid, naphthalene tricarboxylic acid and naphthalene tetracarboxylic acid; alicyclic carboxylic acids such as cyclohexane-3,5-diene-1,2-carboxylic acid and hexahydroterephthalic acid; succinic anhydride; Maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, heptic anhydride, hymic anhydride, trimellitic anhydride, pyromellitic anhydride, methylcyclohexenetricarboxylic acid Examples thereof include polycarboxylic anhydrides such as anhydrides, and methyl esters, ethyl esters, vinyl esters, and acid chlorides thereof.

Examples of polyhydric alcohols include ethanediol, propanediol, butanediol, pentanediol, hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol heptanediol, octanediol, nonanediol, decanediol. Diol, dodecanediol, cyclohexanediol, glycerin, trimethylolethane, trimethylolpropane, trishydroxymethylaminomethane, pentaerythritol, dipentaerythritol, hexamethylolmelamine, hexaethylolmelamine, tetramethylolbenzoguanamine, tetraethylolbenzoguanamine, etc. Aliphatic alcohol, hydrogenated bisphenol A, bisphenol A, etc. It can be.

Examples of oxy acids include glycolic acid, lactic acid, glyceric acid, malic acid, tartaric acid, gallic acid,
Examples include benzyl acid, p-hydroxybenzoic acid, m-hydroxybenzoic acid, o-hydroxybenzoic acid, and methyl esters, ethyl esters, vinyl esters, and acid chlorides thereof.

Examples of cyclic monomers include β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, 8-octonolide, 11-undecanolide, 12-dodecanolide, 15-pentadecanolide,
α-methyl-β-propiolactone, β-methyl-α-
And propiolactone, α, α-dimethyl-β-propiolactone. Furthermore, there is no problem with using optically active polyesters or polyesters produced by living organisms. Examples of these polyesters include poly ((R)-
3-hydroxybutyrate), poly (3-hydroxyalkanate) and the like.

[0013] The molecular weight of the polyester used in the present invention is not particularly limited as long as it can react with the hydrolase, but it is 300 to 1,000,000, particularly 50, in terms of polystyrene equivalent number average molecular weight determined by GPC.
A range from 0 to 300,000 is preferred.

As the lactone used in the present invention, various lactones can be used without any particular limitation. For example, β-propiolactone, γ-butyrolactone, δ-
Valerolactone, ε-caprolactone, 8-octonolide, 11-undecanolide, 12-dodecanolide, 15-pentadecanolide, α-methyl-β-propiolactone, β
-Methyl-α-propiolactone, α, α-dimethyl-
β-propiolactone.

The present invention utilizes an ester synthesis reaction catalyzed by a hydrolase. Therefore,
The hydrolase used in the present invention is not particularly limited as long as it catalyzes an ester synthesis reaction.Examples include carboxyesterase, lipase, phospholipase, acetylesterase, pectinesterase, cholesterol esterase, tannase, and monoacylglycerol lipase. , Lactonase, lipoprotein lipase, and other EC (enzyme number) 3.1 groups (see Maruzo and Tamiya, “Enzyme Handbook” Asakura Shoten (1982) and the like). Hydrolases classified into the EC 3.2 group acting on compounds, hydrolases classified into the EC 3.3 group such as epoxide hydrolase, aminopeptidase, chymotrypsin, trypsin, plasmid Min, mention may be made of hydrolytic enzymes classified in EC3.4 group acting on peptide bonds, such as subtilisin, hydrolases are classified into EC3.7 group such as furo retinoic hydrolase like.

Among the above esterases, an enzyme that hydrolyzes glycerol esters to release fatty acids is particularly called a lipase. Lipases have the advantages of catalyzing the ester synthesis reaction with high yield and being available at a low cost. Therefore, it is preferable to use lipase also in the method for producing the polyester of the present invention.

Although lipases of various origins can be used, Pseudomonas (Pseudomonas) is preferred.
nas), Alcaligenes, Achromobacter, Candida
Lipases obtained from microorganisms such as genus, Aspergillus genus, Rhizopus genus, Mucor genus, lipase obtained from plant seeds, lipase obtained from animal tissues, pancreatin, stearpsin, etc. Can be mentioned. this house,
It is desirable to use lipases derived from microorganisms of the genus Pseudomonas, Candida and Aspergillus. In the present invention, two or more types of hydrolases may be used as a mixture, and an enzyme immobilized by a known method may be used in order to stabilize the enzyme and facilitate recovery after the reaction. Is also possible.

In the present invention, a solvent can be used if necessary. As the solvent, those which do not hinder the activity of the hydrolase are preferable, for example, hexane, cyclohexane, benzene, toluene, dioxane, tetrahydrofuran, isopropanol, t-amyl alcohol,
Examples include acetonitrile, ethyl acetate, ether, and isopropyl ether.

In the modification step of the present invention, there is no problem even if the lactone and the polyester maintain a solid or liquid state and also maintain a dispersed state with the solid hydrolase.

In the present invention, the lactone is preferably used in an amount of 1 to 10,000% by weight, more preferably 10 to 1,000% by weight, based on the weight of the polyester. The reaction temperature is preferably -10 to 120 ° C, in which the enzyme is not inactivated, and particularly preferably 2 to 120 ° C.
0-80 degreeC is desirable.

In the present invention, the amount of the hydrolase to be added may be appropriately adjusted depending on the ester synthesizing ability of the hydrolase used, but is preferably 0.01 to 100% by weight based on the total amount of the polyester and the lactone. Preferably, it may be 0.1 to 10% by weight. At this time, even if the enzyme is used in a large amount, no side reaction occurs, and there is no trouble in the purification operation of the obtained modified polyester.

The modified polyester obtained in the present invention has a number average molecular weight of 300 to 300,000, usually 500 to 1 in terms of polystyrene equivalent molecular weight determined by GPC.
It is in the range of 00,000.

[0023]

The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. (Example 1) Poly (ε-caprolactone) (number-average molecular weight 8,000 determined by GPC in terms of polystyrene) 1
The gram was dispersed in 10 mL of isopropyl ether, to which 0.05 gram of lipase and 1 gram of 12-dodecanolide (13-membered lactone) were added. This was heated at 60 ° C. for 72 hours.
Thereafter, 50 mL of chloroform was added, the enzyme was removed by filtration, and the filtrate was concentrated under reduced pressure. This was poured into a large amount of methanol to precipitate a polymer. The polymer was recovered by filtration and dried under vacuum. The yield was 1.7 g, and the number average molecular weight determined by GPC in terms of polystyrene was 10,000.
It was 0. According to 1H NMR, the composition ratio was 60:40 (molar ratio), 13
C NMR confirmed that a random polymer had been formed. (Example 2) Poly (ε-caprolactone) (number average molecular weight determined by GPC in terms of polystyrene of 20,000)
1.1 g was dispersed in 10 mL of isopropyl ether, and 0.1 g of lipase and 2.5 g of 15-dodecanolide (16-membered lactone) were added thereto. This was heated at 60 ° C. for 72 hours. Thereafter, 50 mL of chloroform was added, the enzyme was removed by filtration, and the filtrate was concentrated under reduced pressure. This was poured into a large amount of methanol to precipitate a polymer. The polymer was recovered by filtration and dried under vacuum. Yield 3.0 grams, G
The number average molecular weight determined by PC in terms of polystyrene is 9,
000. 1H NMR confirmed that the composition ratio was 55:45 (molar ratio), and 13C NMR confirmed that a random polymer was formed. (Example 3) Poly (butylene adipate) (number average molecular weight 50,000 determined by GPC in terms of polystyrene)
Two grams were dispersed in 20 mL of isopropyl ether, and 0.1 g of lipase and 2 g of ε-caprolactone were added thereto. This was heated at 60 ° C. for 72 hours. Thereafter, 50 mL of chloroform was added, the enzyme was removed by filtration, and the filtrate was concentrated under reduced pressure. This was poured into a large amount of methanol to precipitate a polymer. The polymer was recovered by filtration and dried under vacuum. The yield was 3.3 g, and the number average molecular weight determined by GPC in terms of polystyrene was 30,000. 1H
It was confirmed by NMR that the composition ratio was 50:50 (molar ratio) and that 13C NMR produced a random polymer. Example 4 2 g of poly ((R) -3-hydroxybutyrate) (number average molecular weight 50,000 determined by GPC in terms of polystyrene) was added to 20 mL of isopropyl ether.
And 0.1 g of lipase and 2 g of 12-dodecanolide were added thereto. This was heated at 60 ° C. for 120 hours. Thereafter, 50 mL of chloroform was added, the enzyme was removed by filtration, and the filtrate was concentrated under reduced pressure. This was poured into a large amount of methanol to precipitate a polymer. The polymer was recovered by filtration and dried under vacuum. Yield 3.8 grams, GP
The number average molecular weight calculated from C in terms of polystyrene is 70,
000. 1H NMR confirmed that the composition ratio was 55:45 (molar ratio), and 13C NMR confirmed that a random polymer was formed.

[0024]

According to the present invention, various modified polyesters can be produced under simple and mild conditions.

Claims (2)

[Claims] 1. A method for producing a modified polyester, comprising reacting a lactone with a polyester in the presence of a hydrolase. 2. The method according to claim 1, wherein the hydrolase is lipase.